Calcium bones and antlers.

[John Gryphon]

I have seen pregnant cows chewing on bones previously and knew deer did also but only today I proved it to myself. She picked it up several times for a chew. Poor light as usual.

 

[Freeforester]

Recycling trace elements and calcium; some areas they’ve been known to raid ground nesting bird nests.

 

[CAVHUNT]

Knew they did it but never got to see it being done. Seems the stars aligned for you.

 

[John Gryphon]

and knew deer did also but only today I proved it to myself.,its only taken a friggin` lifetime . Im still waiting on the white one.